A smart parking assist system (SPAS) is a system that searches a parking slot using an ultrasonic sensor and assists a driver in parking using trajectory creation and automatic steering control to park a vehicle in the searched slot. In this smart parking assist technology, a study regarding a method of utilizing a parking line to determine an environment has been actively conducted.
However, in the smart parking assist system (SPAS) according to the related art, the search starts after a type and a direction of parking slot are selected, and a target parking slot is selected after the vehicle passes through the target parking slot, creating a more complex system and decreasing driver convenience. In other words, according to the related art, multiple switch manipulations are required by the driver to select parking modes (e.g., reverse parking, parallel parking, and forward parking) and parking directions (e.g., left and right).
In addition, according to the related art, a process of scanning using the ultrasonic sensor while moving the vehicle forward to obtain parking slot information is required. Further, in the related art, a parking control starts after the vehicle passes from the parking slot by a predetermined distance after a parking search starts in front of the parking slot by a predetermined distance, which is inconvenient to a user. Additionally, in the related art, the parking control starts by backward movement after the vehicle passes from the parking slot by a predetermined distance, such that a movement distance, a required time, the number of forward movements, and the number of backward movements, and the number of turns are increased until the parking of the vehicle is completed.